1. Technical Field
Embodiments of affinity based sensors are disclosed herein. In particular, but not exclusively, embodiments of backside stimulated CMOS (Complementary Metal Oxide Semiconductor) type sensors are disclosed herein. In embodiments, the sensors utilize their background current to measure affinity related stimuli to their backside surfaces.
2. Background Information
Affinity based detection is a fundamental method of identification and measurement. For example, affinity based detection may be used to identify and measure the abundance of biological and biochemical analytes. It is an important analytical method in many fields of endeavor including biotechnology. Affinity based biosensors utilize selective interaction and binding of a target analyte with immobilized capturing probes to specifically capture the target analyte onto a solid surface. Such specific capturing generates detectable signals based on the captured analytes. The generated signals correlate with the presence of target analytes, e.g., ions, toxins, polymers, hormones, DNA strands, protein, cells, etc., and hence are used to estimate the analytes' abundance.
To create the target-specific signals, the target analytes in a sample first collide with a capturing layer that is equipped with probes, bind to the probes, and initiate a transduction process, i.e., a process that produces measurable signals, e.g., electrical, mechanical or optical signals, that are produced solely by the captured entities. The signals are then processed by various means, for example, semiconductor based signal processing techniques.
Various affinity based sensors are known in the arts. However, there is a general need in the art for new and useful affinity based sensors.